Although there’s no evidence to suggest that Mac sales have slowed thus far, analyst Gene Munster cited “low visibility” into next year’s environment as reason to adopt a conservative approach and model Mac sales growth to drop from 43% year-over-year in 2008 to 10% year-over-year in 2009.

“The primary reason for our universe-wide estimate cuts is that the economic and consumer spending outlook has deteriorated significantly over the last month, which we expect to continue through 2009,” he wrote in a note to clients.

Specifically, Munster expects Apple to generate 2009 calendar year revenues of $41.22 billion on sales of 11 million Macs, 45 million iPhones, and 41.2 million iPods. He maintains shares of Apple as a “Buy”, but lowered his 12-month price target from $250 to $235.